摘要
在地形比较复杂的白龙江流域，利用2011年4、7、10月份的MODIS数据产品，采用温度植被干旱指数法TVDI，计算了流域3个月上、中、下旬的TVDI指数，并且借助农业气象站点的土壤墒情数据对TVDI结果进行了回归验证，以此划分了流域的土壤湿度等级，并在此基础上分析了流域土壤湿度的时空变化。研究表明：利用MODIS数据产品，采用TVDI法反演土壤湿度状况，适用于地表植被覆盖较高的白龙江流域，且反演参数容易获取，很大程度降低了土壤湿度的遥感反演的复杂性，有利于大、中尺度的应用研究；反演得到TVDI结果分布情况与流域0～10cm实测的土壤相对湿度具有中等相关关系，相关系数为0．73，说明该方法反演的土壤湿度能够反映地表表面O～10cm深度的相对土壤湿度情况；受海拔高度的影响，流域的TvDI结果和高程值呈现出一种负相关，相关系数为～0．75，即土壤湿度和海拔高度呈现出一种正相关关系，随着海拔高度的变化，土壤湿度呈现出一种明显地分异规律。
The research tried to retrieve the soil moisture in Bailong Basin by using the MODIS products in April, July, October in 2011. Based on the underlying surface characteristics of the study area and the model of soil moisture retrieval by remote sensing, the Temperature-Vegetation Dryness Index （TVDI） model was adopted to calculate the soil moisture of every day in April, July, and October in 2011. The soil moisture data of the agricultural meteorological stations was applied to verify TVDI results on the regres- sion model, and the result provided a basis for the division of watershed soil moisture level and the analysis of the temporal and spa- tial variation of soil moisture in Baitong Basin. The results showed that the TVDI Model was suitable for Bailong Basin, which has high vegetation cover; using MODIS products could predigest the retrieval parameters, reduce the complex of soil moisture retrievals and ensure the application for large, middle-scale region; the distribution of TVDI results had moderate correlation with measured soil moisture of 0~10 cm, and the correlation coefficient was 0. 73. This indicated that the method of soil moisture retrieval could re- fleet the soil relative humidity of the surface depth of 0~ 10 cm; Affected by the altitude, the TVDI results and elevation values showed a negative correlation and the correlation coefficient was --0.75 ;on the other hand, the soil moisture and altitude showed a positive correlation and a clear differentiation law with the altitude change.
出处
《节水灌溉》
北大核心
2013年第12期23-27,32,共6页
Water Saving Irrigation
